Modelling, characterization and development of new magnetorheological elastomers with enhanced vibration control performance

Magnetorheological elastomers (MRE) are a category of smart materials that can adjust their mechanical properties according to the intensity of an external magnetic field. The aim of this project is to develop new magnetorheological elastomers with improved isolation efficiency for applications in the marine industry. For this reason, novel silicon isotropic/anisotropic and anisotropic/anisotropic, with particles aligned at different directions, composite MR elastomers were manufactured. The samples were tested under pure compression and combined shear/compression loading mode, using an inclined prototype isolator device, to examine the principal elastic axis stiffness kp/kq and damping ratio cp/cq . MR effect of dynamic stiffness is higher in pure compression isolator than the inclined isolator while MR effect of tangent of loss angle tanδ is higher in inclined isolator than pure compression. For the inclined test, the highest MR effect of 48% for K’ and 68% for K’’, is observed for the pure anisotropic sample and the lowest of 26% and 30% respectively for the isotropic MRE. Anisotropic/anisotropic parallel configuration has the same zero field static stiffness, lower dynamic stiffness, higher tanδ and same MR effect with anisotropic MRE. For all samples, the principal elastic axis stiffness kp/kq and damping ratio cp/cq changes with the magnetic field. A nonlinear viscoelastic model was also developed using receptance and mobility instead of stiffness and dashpot, to express the moduli of elasticity in respect to the applied force. Finally, a single degree of freedom mass-isolator with composite samples was simulated to show the enhanced vibration isolation properties of the composite samples